Minimum Remove to Make Valid Parentheses ( LeetCode ) Problem Solution.

Example 1:

Input: s = "lee(t(c)o)de)"
Output: "lee(t(c)o)de"
Explanation: "lee(t(co)de)" , "lee(t(c)ode)" would even be accepted.

Example 2:

Input: s = "a)b(c)d"
Output: "ab(c)d"

Example 3:

Input: s = "))(("
Output: ""
Explanation: An empty string is additionally valid.

Example 4:

Input: s = "(a(b(c)d)"
Output: "a(b(c)d)"

Constraints:

1 <= s.length <= 10^5
s[i] is one amongst '(' , ')' and lowercase English letters.

Solution :-

class Solution:
def minRemoveToMakeValid(self, s: str) -> str:
st=[]
res=[c for c in s]

for i in range(len(s)):
if(s[i]=='('):
st.append(i)
elif(s[i]==')'):
if st:
st.pop()
else:
res[i]=''

for j in range(len(st)):
res[st[-j]]=''

return ''.join(res)

Runtime: 92 ms, faster than 93.99% of Python3 online submissions for Minimum Remove to form Valid Parentheses.

Memory Usage: 15.8 MB, but 100.00% of Python3 online submissions for Minimum Remove to form Valid Parentheses.

Minimum Remove to Make Valid Parentheses ( LeetCode ) Problem Solution.